Fighting ignorance since 1973.(It's taking longer than we thought.)

Are aphids born pregnant?

November 24, 1989

Dear Cecil:

I heard aphids are born pregnant. Is this true? If so, how does it work?

Lilian Wentworth, Silver Spring, Maryland

Illustration by Slug Signorino

Cecil replies:

You think your life is miserable, cucumber, just be glad you’re not an aphid. Not only are they born pregnant, they’re pregnant without benefit of sex. Not that sex with an aphid sounds like much of a treat. Two things are at work here: parthenogenesis and paedogenesis.

Parthenogenesis, also known as virgin birth, is rare in humans (one known case) but common in insects. The baby bugs, all of which are female, develop from single cells in mom’s body. The advantage of this is that reproduction is very quick — none of this flowers and perfume jive — which helps when you’ve got as many natural enemies as aphids have.

Paedogenesis — pregnancy in the young — speeds up the process even more. “Although the young are not born until the aphid has reached the adult stage,” it says here, “their development may begin before she is born while she is still in the ducts of the grandparental generation.” Aphids can give birth ten days after having been born themselves. The baby showers must be murder.

A question

Dear Cecil:

With regard to your column about aphids being born pregnant, you said, “virgin birth is rare in humans (one known case).” Aren’t you going to tell us about the one known case?

— Alison True, Chicago

Well, I suppose I could, Alison. But it’s been pretty well publicized.